The variety of fodder sorrel Rumex OK 2 (Rumex patientia L. x Rumex tianschanicus A. Los.) was cultivated in Ukraine. Since 90th years of 20th century, this crop plant has been experimentally grown in the CR. It is used as energetic source for biogas plants. The goal of this experiment was to investigate the growth dynamic and yield of the sorrel as well as its nutritive content and the ensiling possibility. It was proved that the fodder sorrel is fast growing species – its yield represented 30 q/month- with good ensilability. The content of WSC in the sorrel is sufficient and the amount of heat of combustion is similar to maize.